A damper for a vehicle is interposed between a vehicle body and a vehicle wheel of the vehicle and suppresses vibrations of the vehicle body and the vehicle wheel by exerting a damping force when extending/contracting. Among such dampers, there are passive dampers that exert a damping force with preset damping force characteristics (characteristics of the damping force generated by the damper relative to an extension/contraction speed of the damper), as well as dampers that vary the damping force in order to enhance the riding comfort in the vehicle and control the vehicle body posture.
As disclosed in JP6-173996A, dampers that vary the damping force are provided with an extension-side solenoid valve that controls the pressure within an extension-side chamber, and a compression-side solenoid valve that controls the pressure within a compression-side chamber. The opening of the extension-side solenoid valve and the opening of the compression-side solenoid valve are regulated by a damper control device, and the damping force exerted by the damper is controlled by the damper control device.